JP2008141085A - Apparatus for treating substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus capable of measuring the temperature and temperature distribution of a substrate that is being heat-treated. <P>SOLUTION: In the apparatus, a plurality of substrates W are heat-treated simultaneously with a plurality of heat treatment units 10a, 10b, 10c, 10d, and the tips of fiber scopes 16a, 16b, 16c, 16d are arranged for each heat treatment unit so that each substrate is positioned in the viewing angle of the objective lens at the tip. Eye-piece section sides 20a, 20b, 20c, 20d of respective fiber scopes are optically connected to a single thermography system 24 via a changeover device 22 for alternately changing a transmission line; and the temperature and the temperature distribution of the substrate being treated by each heat treatment unit are each measured for monitoring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for performing a heat treatment or the like on a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, or the like.

  In the manufacturing process of semiconductor devices and liquid crystal displays, products are manufactured by applying a series of processes such as resist coating, exposure, development, and etching to substrates such as semiconductor wafers and glass substrates using photolithography technology. ing. Among these series of processes, for example, a plurality of processing units that respectively perform resist coating processing and development processing and heat treatment associated therewith, and a plurality of transfer robots that transfer substrates between these processing units are provided. Substrate processing apparatuses (generally called “coaters and developers”) are widely used. An exposure apparatus is also provided in such a substrate processing apparatus, and a series of processes from resist coating to exposure and development are performed.

  When manufacturing the semiconductor device or the liquid crystal display as described above, for example, when heat treating the substrate, the substrate is placed directly or close to the upper surface of the heat plate (hot plate) and is installed in the heat plate. The substrate is heated by the heater. In such a substrate heat treatment step, for example, the temperature distribution of the substrate during the heat treatment performed after the photoresist coating process affects the film thickness of the resist formed on the substrate surface. Further, the temperature distribution of the substrate during the heat treatment (post-exposure bake (PEB) processing) of the substrate performed after the exposure for the purpose of uniformly diffusing the product generated by the photochemical reaction due to the exposure inside the resist film, or after the development processing. The temperature distribution of the substrate during the heat treatment of the substrate affects the width of the pattern line formed in the resist film. In addition, it is known that the temperature and temperature distribution of the substrate at various points in time affect various processing qualities such as the oxide film thickness and film quality after heat treatment. Therefore, in order to monitor whether the substrate is heated to a constant temperature and uniformly, it is necessary to measure the temperature and temperature distribution of the substrate actually processed. Furthermore, not only the temperature and temperature distribution of the substrate during the heat treatment, but also the temperature and temperature distribution of the substrate during the photoresist coating process affect the processing quality such as the thickness of the resist formed on the substrate surface.

Here, as a method of measuring the temperature of the substrate, conventionally, the temperature of the substrate is measured by directly attaching the detection end of a thermocouple or a resistance temperature detector to the substrate, or a radiation thermometer is used. A method of measuring the temperature of the substrate without contact with the substrate is used (for example, see Patent Document 1). When viewing the temperature distribution of the substrate, a plurality of thermocouples or resistance temperature detectors are attached to the substrate, and the temperatures at a plurality of locations on the substrate are individually measured.
Japanese Patent Laying-Open No. 2005-11852 (page 6-7, FIG. 1, FIG. 3, FIG. 4)

  In the measurement of the temperature of the substrate by a thermocouple, a current is passed through the thermocouple, the voltage value at that time is measured, and this voltage value is converted into temperature. In the measurement of the substrate temperature by the resistance temperature detector, a current is passed through the resistance temperature detector, the current value at that time is measured, and the current value is converted into temperature. Therefore, since the temperature measurement is performed by connecting the sensor unit and the measurement unit of the thermocouple with a conductive wire, it is impossible to directly measure the temperature of the substrate during the heat treatment. In recent years, there are thermocouples that do not require conductive wires, but even when such thermocouples are used, it is difficult to directly measure the temperature of the substrate during heat treatment.

  On the other hand, if a radiation thermometer is used, it is possible to measure the temperature of the substrate during the heat treatment. However, since the radiation thermometer has no spatial resolution, a single radiation thermometer cannot see the temperature distribution of the substrate. For this reason, when using a radiation thermometer to look at the temperature distribution of the substrate, it is necessary to install a plurality of radiation thermometers. It is difficult. Thus, in the method using a radiation thermometer, it is difficult to see the temperature distribution of the substrate.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a substrate processing apparatus capable of measuring the temperature and temperature distribution of a substrate during processing such as heat treatment.

  According to a first aspect of the present invention, there is provided a substrate processing apparatus for simultaneously processing a plurality of substrates by a plurality of processing units that perform the same type of processing, wherein a distal end portion of a fiberscope (endoscope) is provided for each processing unit. Via a switching means that is arranged so that the substrate is positioned within the viewing angle of the objective lens at the tip, and the eyepiece side of each fiberscope is switched to a single thermography, selectively switching the transmission path Each of them is optically connected, and the temperature and temperature distribution of the substrate processed in each processing unit are measured and monitored.

  According to a second aspect of the present invention, in the substrate processing apparatus of the first aspect, the processing unit is a heat treatment unit that heats the substrate with a heat plate.

  The invention according to claim 3 is the substrate processing apparatus according to claim 1 or 2, wherein the temperature and temperature distribution of each substrate measured by the thermography are the temperature and temperature distribution of a substrate processed normally. A control unit that compares each of them, specifies a processing unit that has processed the substrate when an abnormality is detected in the temperature or temperature distribution of the substrate, and controls the processing unit not to process the substrate. It is characterized by having.

  In the substrate processing apparatus according to the first aspect of the present invention, infrared energy (thermal energy) radiated from the surface of the substrate being processed by the processing unit is transmitted to the thermography through the fiberscope, and is being processed by the thermography. The temperature and temperature distribution of the substrate can be measured without contact with the substrate. Further, by switching the switching means, it is possible to measure and monitor the temperature and temperature distribution of a plurality of substrates simultaneously processed by a plurality of processing units by a single thermography. In this case, since the temperature and temperature distribution of each substrate processed by a plurality of processing units are measured by a common thermography, it is necessary to perform temperature calibration of the thermography when comparing the temperature and temperature distribution of each substrate. No. In addition, each processing unit only has a fiberscope tip, and only one thermography needs to be installed outside the processing unit. This saves space for the processing unit and saves equipment space. Can be used.

  In the substrate processing apparatus according to the second aspect of the invention, the temperature and temperature distribution of a plurality of substrates heat-treated by a plurality of heat treatment units can be measured and monitored by a single thermography.

  In the substrate processing apparatus of the invention according to claim 3, the control means compares the temperature and temperature distribution of each substrate measured by thermography with the temperature and temperature distribution of the substrate processed normally, respectively. When an abnormality in temperature or temperature distribution occurs, the abnormality can be detected. Further, when an abnormality is detected in the temperature or temperature distribution of the substrate, the substrate is not processed in the processing unit that processed the substrate, and the substrate is processed in the other processing units. As a result, the product yield can be improved.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention.

  The substrate processing apparatus includes a plurality of heat treatment units 10a, 10b, 10c, and 10d. Each of the heat treatment units 10a, 10b, 10c, and 10d includes a heat plate 12 on which the substrate W is placed, and a chamber 14 that covers the entire upper surface of the heat plate 12 so as to be openable and closable. Although detailed explanation and illustration are omitted, the heat plate 12 is provided with a plurality of, for example, three support pins that go up and down through the heat plate 12, and the substrate W is carried in by the raising and lowering operations of the support pins. In addition, the substrate W is transferred between the substrate transfer robot and the heat plate 12 during unloading. The substrate W is placed directly on the upper surface of the heat plate 12 or is supported by a plurality of small protrusions (not shown) fixed on the upper surface of the heat plate 12, It is placed in close proximity through a slight gap. The chamber 14 is provided with a gas supply means for supplying a purge gas such as nitrogen gas into the chamber 14 and a gas discharge means for discharging the gas to the outside.

  The front ends 18a, 18b, 18c, and 18d of the fiber scopes 16a, 16b, 16c, and 16d are attached to the respective chambers 14. The front ends 18a, 18b, 18c, and 18d of the fiber scopes 16a, 16b, 16c, and 16d face the surface of the substrate W placed on the heat plate 12, and the substrate W is positioned within the viewing angle of the objective lens. Are arranged as follows. The eyepiece side 20a, 20b, 20c, 20d of each of the fiberscopes 16a, 16b, 16c, 16d is optically connected to a single thermography 24 disposed outside the heat treatment unit via a switcher 22, respectively. ing. The fiberscopes 16a, 16b, 16c, and 16d are configured to be selectively optically connected to the thermography 24 by the transmission path switching operation by the switcher 22, respectively. The thermography 24 is connected to a CPU 26, and a memory 28 and a color monitor 30 are connected to the CPU 26. A main controller 32 is connected to the CPU 26.

  The switching of the transmission path by the switch 22 is performed at regular intervals, for example. Infrared energy radiated from the surface of the substrate W that is simultaneously heat-treated by the heat treatment units 10a, 10b, 10c, and 10d is sequentially transmitted to the thermography 24 via the fiber scopes 16a, 16b, 16c, and 16d, and is being heat treated. The temperature and temperature distribution of each substrate W are sequentially measured by the thermography 24, and the measurement signal is sent to the CPU 26. The CPU 26 specifies which heat treatment unit the measurement signal is for the substrate under heat treatment, sends the data to the color monitor 30, and an image representing the temperature and temperature distribution of the substrate W under heat treatment is displayed on the color monitor. 30. At this time, the color monitor 30 may simultaneously display images 34a, 34b, 34c, and 34d representing the temperature and temperature distribution of the substrate W that has been heat-treated by the respective heat treatment units 10a, 10b, 10c, and 10d. Then, an image representing the temperature and temperature distribution of the substrate W that has been heat-treated in each of the heat treatment units 10a, 10b, 10c, and 10d may be sequentially displayed one by one at regular intervals. Alternatively, an arbitrary heat treatment unit may be designated and an image representing the temperature and temperature distribution of the substrate W that has been heat treated by the heat treatment unit may be displayed on the color monitor 30.

  When the substrate processing apparatus shown in FIG. 1 is used, the temperature and temperature distribution of the substrate W that is simultaneously heat-treated by the plurality of heat treatment units 10a, 10b, 10c, and 10d are measured without contact with the substrate W by a single thermography 24. It is possible to monitor whether or not an abnormality has occurred in the temperature or temperature distribution of the substrate W that is simultaneously heat-treated by the plurality of heat treatment units 10a, 10b, 10c, and 10d. In this monitoring, for example, a threshold value for determining whether the temperature or temperature distribution of the substrate W is abnormal is stored in the memory 28, and the temperature of the substrate W during the heat treatment measured by the thermography 24 in the CPU 26. Alternatively, the measurement value of the temperature distribution is compared with the threshold value read from the memory 28. When it is determined that the measurement value obtained by the thermography 24 is abnormal, a signal is sent from the CPU 26 to the main controller 32, and a control signal output from the main controller 32 is used, for example, to treat the abnormal substrate after the heat treatment step. Immediately, the process moves to the inspection process, returns to the previous process, or adjusts the process conditions when processing a substrate having an abnormality in the subsequent process.

  2 and 3 show an example of a substrate processing system in which a substrate processing apparatus having the configuration shown in FIG. 1 is incorporated, and shows a sequence in which the substrates move between the processing units. It is a figure explaining the substrate processing process. The series of substrate processing steps shown in FIGS. 2 and 3 are a resist coating process and a developing process, and a heat treatment and an exposure process associated therewith, and an apparatus called a “coater & developer” is generally used for an exposure apparatus. It is done side by side. FIG. 2 shows from the resist coating process to the exposure process, and FIG. 3 shows from the exposure process to the development process. Hereinafter, processing operations in the substrate processing system will be described, but detailed description and illustration of each processing unit will be omitted.

  First, in the indexer unit 36, an unprocessed substrate is taken out from the carrier placed on the mounting table by the substrate transfer mechanism, the substrate is transferred from the substrate transfer mechanism to the transfer robot, and the substrate is transferred to the cool plate 38 by the transfer robot. The substrate is cooled by the cool plate 38. The cooled substrate is transferred to the coating processing unit 40 by the transfer robot. In the coating processing unit 40, a coating solution for forming an antireflection film is applied to the surface of the substrate.

  When the coating process in the coating process unit 40 is completed, the substrate is transferred to the heat treatment unit 42 by the transfer robot. Then, the substrate is heated by the heat plate in the heat treatment unit 42 to dry the coating liquid on the substrate, and a base antireflection film is formed on the substrate. In this heat treatment step, the temperature and temperature distribution of each substrate heat-treated simultaneously by the plurality of heat treatment units 42 are measured by a single thermography 44 using an apparatus having the configuration shown in FIG. 1, and the temperature of each substrate is measured. And monitor the temperature distribution for abnormalities. The substrate after the heat treatment is transferred to the cool plate 46 by the transfer robot and cooled by the cool plate 46.

  The substrate cooled by the cool plate 46 is transferred to the coating processing unit 48 by the transfer robot. In the coating processing unit 48, a photoresist is coated on the surface of the substrate. In this coating processing step, the temperature and temperature distribution of each substrate that is simultaneously coated by a plurality of coating processing units 48 are measured by a single thermography 50, and whether there is any abnormality in the temperature and temperature distribution of each substrate. To monitor.

  When the coating process in the coating processing unit 48 is completed, the substrate is transferred to the heat treatment unit 52 by the transfer robot. Then, the substrate is heated by the heat plate in the heat treatment unit 52, and the solvent component in the photoresist formed on the substrate is evaporated and removed, whereby a resist film is formed on the substrate. In this heat treatment step, the temperature and temperature distribution of each substrate heat-treated simultaneously by the plurality of heat treatment units 52 are measured by a single thermography 54 using the apparatus having the configuration shown in FIG. 1, and the temperature of each substrate is measured. And monitor the temperature distribution for abnormalities. The substrate after the heat treatment is transferred to the cool plate 56 by the transfer robot and cooled by the cool plate 56. The substrate cooled by the cool plate 56 is transported to the film thickness measuring unit 58 by the transport robot, and the thickness of the resist film formed on the surface of the substrate in the film thickness measuring unit 58 is measured by the film thickness meter. If there is no abnormality in the thickness of the resist film measured by the film thickness meter, the substrate on which the resist film is formed is conveyed to the exposure apparatus 60 through an interface unit (not shown). Pattern exposure processing is performed. On the other hand, when an abnormality in film thickness is detected, the substrate is moved to, for example, a regeneration process.

  In each processing step, the temperature and temperature measured by the thermography 44, 50, 54 of each substrate processed simultaneously by the plurality of processing units 42, 48, 52 are respectively stored in the memory. It is preferable that the temperature history of the substrate can be traced. In this way, when an abnormality in the thickness of the resist film formed on the surface of the substrate is detected by measurement with a film thickness meter, the temperature and temperature distribution of the substrate on which the resist film having a normal thickness is formed. Is compared with the temperature and temperature distribution of the substrate where the film thickness was abnormal, the resist film thickness abnormality was caused by the substrate temperature or temperature distribution abnormality in any processing unit in any processing process. You can identify what you are doing. When a processing unit that has processed a substrate having an abnormality in temperature or temperature distribution is identified, the substrate processing is not performed in the processing unit, and the substrate is processed in other processing units. By doing so, the product yield can be improved.

  The substrate for which the pattern exposure processing has been completed is returned from the exposure apparatus 60 to the original apparatus through the interface unit again. Then, as shown in FIG. 3, the substrate is transferred to the heat treatment unit 62 by the transfer robot. In the heat treatment unit 62, a heat treatment (post-exposure baking (PEB) treatment) for uniformly diffusing a product generated by the photochemical reaction by the exposure into the resist film is performed. In this heat treatment step, the temperature and temperature distribution of each substrate heat-treated simultaneously by the plurality of heat treatment units 62 are measured by a single thermography 64 using the apparatus having the configuration shown in FIG. And monitor the temperature distribution for abnormalities.

  The substrate after the heat treatment is transferred to the cool plate 66 by the transfer robot, cooled by the cool plate 66, and then transferred to the development processing unit 68. In the development processing unit 68, a developing solution is supplied onto the substrate, and the exposed resist film formed on the substrate surface is developed. Then, the substrate after the development processing is transferred to the heat treatment unit 70 by the transfer robot, and the substrate is heated by the heat plate in the heat treatment unit 70. In this heat treatment step, the temperature and temperature distribution of each substrate heat-treated simultaneously by a plurality of heat treatment units 70 are measured by a single thermography 72 using an apparatus having the configuration shown in FIG. And monitor the temperature distribution for abnormalities. The substrate after the heat treatment is transferred to the cool plate 74 by the transfer robot and cooled by the cool plate 74. The substrate cooled by the cool plate 74 is transferred to the line width measurement unit 76 by the transfer robot, and the line width measurement device measures the pattern line width formed on the resist film on the surface of the substrate. If there is no abnormality in the pattern line width measured by the line width measuring device, the substrate on which the resist pattern is formed is returned to the indexer unit 36 by the transfer robot, and the substrate is transferred from the transfer robot to the substrate transfer mechanism. In the transfer and indexer unit 36, the processed substrate is stored in the carrier mounted on the mounting table by the substrate transfer mechanism. On the other hand, when an abnormality in the pattern line width is detected, for example, the substrate is moved to a reproduction process.

  In each processing step, the temperature and temperature measured by the thermography 64 and 72 of each substrate heat-treated simultaneously by the plurality of heat treatment units 62 and 70 are stored in the memory, and the temperature history of each substrate is stored. You should be able to follow. In this way, when an abnormality in the line width of the resist pattern formed on the surface of the substrate is detected by measurement with a line width measuring device, the temperature of the substrate on which the resist pattern having a normal pattern line width is formed. By comparing the temperature distribution and the temperature distribution of the substrate where the temperature distribution and the pattern line width were abnormal, the line width of the resist pattern was found to be the temperature or temperature of the substrate in any processing unit in any processing step. It is possible to identify whether it is caused by an abnormal distribution. Then, when a processing unit that has processed a substrate having an abnormality in temperature or temperature distribution is specified, the substrate processing is not performed in the processing unit, and the substrate is processed in other processing units. By doing so, the product yield can be improved.

  The present invention can be applied to various heat treatment units that support and heat-treat a substrate on a heat plate. In addition to the heat treatment unit, for example, a coating treatment for applying a photoresist on the surface of the substrate. The unit can also be applied to an apparatus for measuring and monitoring the temperature and temperature distribution of the substrate during the coating process.

It is a schematic diagram which shows one example of embodiment of this invention and shows schematic structure of a substrate processing apparatus. FIG. 2 shows an example of a substrate processing system incorporating a substrate processing apparatus having the configuration as shown in FIG. 1, and a series of substrate processing steps will be described showing the order in which the substrates move between the processing units. FIG. Similarly, it is a figure explaining the series of substrate processing steps by showing the order in which the substrates move between the processing units.

Explanation of symbols

10a, 10b, 10c, 10d, 42, 52, 62, 70 Heat treatment unit 12 Heat plate 14 Chamber 16a, 16b, 16c, 16d Fiberscope 18a, 18b, 18c, 18d Fiberscope tip 20a, 20b, 20c, 20d Eyepiece side of fiberscope 22 Switching device 24, 44, 50, 54, 64, 72 Thermography 26 CPU
28 Memory 30 Color monitor 32 Main controller 34a, 34b, 34c, 34d Image representing substrate temperature and temperature distribution 36 Indexer section 38, 46, 56, 66, 74 Cool plate 40, 48 Coating processing unit 42 Heat treatment unit 58 Film thickness Measurement unit 60 Exposure device 68 Development processing unit 76 Line width measurement unit W substrate

Claims (3)

In a substrate processing apparatus that simultaneously processes a plurality of substrates by a plurality of processing units that perform the same type of processing,
For each processing unit, the distal end of the fiberscope is disposed so that the substrate is positioned within the viewing angle of the objective lens at the distal end, and the eyepiece side of each fiberscope is formed as a single thermography. The substrate processing is characterized in that each is optically connected via a switching means for selectively switching the transmission path, and the temperature and temperature distribution of the substrate processed in each processing unit are respectively measured and monitored. apparatus. The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the processing unit is a heat treatment unit for heating a substrate with a heat plate. In the substrate processing apparatus of Claim 1 or Claim 2,
The temperature and temperature distribution of each substrate measured by the thermography are respectively compared with the temperature and temperature distribution of a normally processed substrate, and processing of the substrate is performed when an abnormality is detected in the temperature or temperature distribution of the substrate. A substrate processing apparatus comprising control means for specifying a processing unit that has been performed and controlling the processing unit not to process the substrate.

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